The present invention generally relates to an improved medical device and methods for treating tissues, and more particularly, to such a medical device and methods for treating hemorrhoids and/or polyps in a patient by delivering RF energy to the lesion sites in association with a therapeutic pressure therapy of a ligation method.
Hemorrhoids, or enlarged veins in the anal area, represent one of the most frequent and familiar anorectal problems seen in primary care office setting. Hemorrhoids occur reportedly in up to 80% to 90% of the US population (Hussain J N, Office Management of Common Anorectal Problems 1999; 26:35-51). The actual prevalence based on epidemiologic studies is more in the range of 40%. The prevalence of hemorrhoids increases with age whereas pregnancy is a common predisposing risk factor for the development of hemorrhoids.
The method of reducing the size of cellular tissues in situ has been used in the treatment of many diseases, or as an adjunct to surgical removal procedures. One method used requires heating the tissues, and causing them to shrink and tighten. It is often less traumatic than surgical procedures and may be the only alternative method, whereby other procedures are unsafe or ineffective. Ablative treatment devices have an advantage because of the use of a destructive energy that is rapidly dissipated and reduced to a non-destructive level by conduction and convection, to forces of circulating fluids and other natural processes.
Devices using microwave energy, radiofrequency energy (RF), ultrasonic energy, cryogenic means, laser energy, and tissues destructive substances have been used to destroy malignant, benign, and other types of cells and tissues from a wide variety of anatomic sites and organs. Tissues treated include isolated carcinoma masses and, more specifically, organs such as the prostate, glandular and stromal nodules characteristic of benign prostate hyperplasia. These devices typically include a catheter or cannula which is used to carry a radiofrequency electrode or microwave energy antenna, through a duct, to the area of treatment, and applying energy diffusively through the duct wall into the surrounding tissues in the targeted directions.
Of particular interest to the present invention are RF therapeutic protocols, which have been proven to be highly effective when used by electrophysiologists for the treatment of tachycardia; by neurosurgeons for the treatment of Parkinson""s disease; and by neurosurgeons and anesthetists for other RF procedures such as Gasserian ganglionectomy for trigeminal neuralgia and percutaneous cervical cordotomy for intractable pains. Radiofrequency treatment, which exposes a patient to minimal side effects and risks, is generally performed after first locating the tissue sites for treatment. Radiofrequency or other energy, when coupled with a temperature control mechanism, can be supplied precisely to the device-to-tissues contact site to obtain the desired temperature for treating a tissue.
Hemorrhoid is a varicose dilatation of a vein of the superior or inferior hemorrhoidal plexus, resulting from a persistent increase in venous pressure. The external hemorrhoid is a varicose dilatation of a vein of the inferior hemorrhoidal plexus, situated distal to the pectinate line and covered with modified anal skin. The internal hemorrhoid is a varicose dilatation of a vein of the superior hemorrhoidal plexus, originating above the pectinate line, and covered by mucous membrane. A more serious case of hemorrhoid, prolapsed hemorrhoid, is an internal hemorrhoid that has descended below the pectinate line and protruded outside the anal sphincter. One of the worst cases, strangulated hemorrhoid, is an internal hemorrhoid which has been prolapsed sufficiently and for long enough time for its blood supply to become occluded by the constricting action of the anal sphincter. Currently, surgical removal is the only method for treating strangulated hemorrhoid, which results in prolonged pain during recovery period. The management of hemorrhoids using conventional approaches has been reported by Dennison AR et al. The American Journal of Gastroenterology 1989; 84:475-481; by Saclarides T J et al. Diseases of the Colon and Rectum 1999; 42:1245-1252; by Griffith C D M et al. British Journal of Surgery 1987; 74:827; and by Salvati E P Diseases of the Colon and Rectum 1999; 42:989-993.
Taylor in U.S. Pat. No. 5,578,047 teaches a hemorrhoid-removing device. Tuffel in U.S. Pat. No. 4,938,221 teaches a hemorrhoid inflammation-reducing device by introducing a coolant for shrinking hemorrhoids. Neither of them discloses a medical device by using a suitable energy to treat a dilated vein to denature and/or shrink it. On the other hand, an alternative for hemorrhoid treatment is by surgically removing the dilated vein by a laser or other means. For a dilated vein, RF energy or other suitable energy can be applied for treating the tissues of the vascular walls, and causing them to shrink, necrosis, and tighten.
Imran in U.S. Pat. No. 5,281,218 entitled xe2x80x9cCatheter having needle electrode for radiofrequency ablationxe2x80x9d teaches a method using a needle electrode that is attached onto a catheter for radiofrequency ablation. Though a needle-like electrode is beneficial to ablate a tissue point for deep lesion, it is not disclosed that the particular needle electrode could possibly combine pressure therapy for proper contact with the target tissues. The xe2x80x9cpressure therapyxe2x80x9d is defined in this invention as application of an appropriate pressure onto the tissues by a medical device, in association with another therapy, such as a RF therapy.
Bidoia in U.S. Pat. No. 5,203,863 teaches an instrument for the ligation of hemorrhoids, which applies pressure to the root of the hemorrhoids. However, the ligature element only applies pressure locally, not on the entire inflammable hemorrhoid tissue. Furthermore, Bidoia does not disclose a combination of thermal therapy with pressure therapy to enhance the treatment of hemorrhoids or polyps.
Clinically, hemorrhoids are traditionally divided into four grades or degrees (as shown by Dennison AR et al., Salvati E P, and Hussain J N). Ligation alone approach for hemorrhoid management can only handle the first or some second grade hemorrhoids. For the higher-grade hemorrhoids, neither ligation alone approach nor thermal treatment alone approach is satisfactory.
Therefore, there is a need for an improved medical device and methods using a combination of ligation techniques and the thermal energy to treat a dilated vein or tissue, such as hemorrhoids while simultaneously applying ligation pressure therapy to the target tissue.
In general, it is an object of the present invention to provide a method and an improved medical device for generating heat, to treat the hemorrhoids, vascular vessels, or other cellular tissues. It is another object of the present invention to provide a method and a device for monitoring the temperature of the medical device, and to control the temperature by utilizing a temperature control mechanism and/or algorithm. The location of the temperature sensor means is preferably at close proximity of the electrode means of the medical device. It is still another object of this invention to provide a method and a device for treating hemorrhoids, vascular walls, or cellular tissues in a patient by applying appropriate pressure to the tissues either by the device itself or by a ligation means associated with the device. It is still a further object to ligate a hemorrhoid tissue and heat the hemorrhoid tissue as an enhanced treatment method.
Briefly, heat is generated by supplying a suitable energy source to a device, which comprises at least one electrode means, in contact with the body tissues. A suitable energy source may consist of radiofrequency energy, microwave energy, ultrasonic energy, infrared energy, alternating current energy, or laser energy. The energy can be applied to the hemorrhoids, vascular walls, or cellular tissues through the electrode means, wherein the electrode means in this invention refers to the metal element for radiofrequency energy, the antenna for microwave energy, the transducer for ultrasound energy, the bulb element for infrared energy, the fiber optic for laser energy, and the like. A DIP (dispersive indifferent pad) type pad or electrode, that contacts the patient, is connected to the Indifferent Electrode Connector on the RF generator for radiofrequency application. Therefore, the RF energy delivery becomes effective when a close circuit from a RF generator through a patient and returning to the RF generator is formed. When using an alternating current outlet, the generator should be grounded to avoid electrical interference. In the case of radiofrequency applications, heat is controlled by the power of the RF energy delivered, the delivery mode, and by the delivery duration. The standard RF energy generator and its applications through the electrode means, to a patient are well known for those who are skilled in the art.
In an optional embodiment, means for generating vibration at the distal section of the device comprises a motor mounted in a cavity of the handle of the device, which has a rotatable motor shaft, an elongated connecting shaft having a first end, to which the distal end portion is connected, and a second end connected to the handle, a weight eccentrically mounted on the motor shaft with respect to the motor shaft axis, so as to rotate eccentrically, so that when the motor shaft rotates, the distal end portion of the device vibrates.
In one embodiment, the device comprises at least one electrode means, wherein the electrode means composes a compressible coil arrangement or a plurality of compressible coils. The coil arrangement is connected to an external RF generating means through an electrical conductor. The contact surface of the coil arrangement to the target tissue is pre-shaped and/or maximized by either flattening the contact surface or by pre-shaping the contact surface in a concave or convex fashion to encircle the essentially round surface of the hemorrhoids and the like. The coil arrangement is compressible so that when the coil electrode is pressed against the tissues or the round surface of a hemorrhoid, an appropriate pressure is exerted onto the tissues while applying the RF energy therapy.
In another embodiment, an elastic dilated ligature element and the like is circumferentially and externally positioned at about the distal section of the delivery tubular shaft of the medical device at a non-deployed state, wherein the dilated ligature element may be pushed off the distal section of the delivery tubular shaft at a deployed state to ligate the root or other desired site of the hemorrhoid.
The method and medical device of the present invention has several significant advantages over other known systems or techniques to treat the hemorrhoids or polyps. In particular, the device system comprising the electrode means, using RF energy as a heat source and simultaneously applying pressure therapy via a dilated ligature element to the tissues, results in a more efficient therapeutic effect for hemorrhoids treatment.